Fig. 1From: Quantitative genetic analysis of the bTB diagnostic single intradermal comparative cervical test (SICCT)Histograms of SICCT component measurements. Frequency distributions for the individual skin thickness measurements, before (a 1 and b 1), and after (a 2 and b 2) inoculation of the tuberculins. Note the change in the x-axis scale for a 2 and b 2 Back to article page